Overview and Calendar for 2017
Overview
Let's look at occultations in 2017!
An occultation is a phenomenon where a star is hidden by the Moon moving through the night sky. In 2017 you can see the occultation of the 1st magnitude star Aldebaran in the constellation Taurus and the 1st magnitude star Regulus in the constellation Leo. In particular, conditions during the occultation of Aldebaran on January 9 are favorable and it can be observed from throughout Japan.
Among the 3 major meteor showers, the Perseid Meteor Shower is ill-suited for observation because the Moon is bright at the peak time. The timing of the peak and the phase of the Moon for the Quadrantid Meteor Shower (January) and the Geminid Meteor Shower (December) are favorable.
Many astronomical events occur in 2017, for example, the occultation of Mercury on July 25, when Mercury gets concealed by the Moon and the partial lunar eclipse on August 8.
| 1 | New Year’s Day [Ganjitsu] (national holiday) |
| 2 | Holiday |
| 3 | Quadrantid Meteor Shower peaks around 23:00. (For Japan, the best visibility will be before dawn on the 4th. About 35 meteors per hour are expected. Because there is no moonlight and the timing of the maximum is not so bad, conditons are relatively good.) |
| 4 | Earth passes perihelion |
| 6 | First Quarter Moon |
| 8 | Mercury at stationary point |
| 9 | Coming-of-Age Day [Seijin-no-hi] (national holiday) / Occultation of Aldebaran |
| 12 | Full Moon / Greatest Eastern Elongation of Venus |
| 19 | Greatest Western Elongation of Mercury |
| 20 | Last Quarter Moon |
| 28 | New Moon |
| 4 | First Quarter Moon |
| 7 | Jupiter at stationary point |
| 11 | Full Moon / National Foundation Day [Kenkoku-Kinen-no-hi] (national holiday) |
| 17 | Venus at Greatest Brillancy |
| 19 | Last Quarter Moon |
| 26 | Annular solar eclipse (not visible from Japan) Reference: Local Prediction of the Solar Eclipse / New Moon |
| 2 | Neptune at conjunction / Venus at stationary point |
| 5 | First Quarter Moon |
| 7 | Mercury at superior conjunction |
| 12 | Full Moon |
| 20 | Vernal Equinox Day [Shunbun-no-hi] (national holiday) / Vernal equinox (Sun’s ecliptic longitude 0°) |
| 21 | Last Quarter Moon |
| 25 | Venus at inferior conjunction |
| 28 | New Moon |
| 1 | Greatest Eastern Elongation of Mercury / Occultation of Aldebaran |
| 4 | First Quarter Moon |
| 6 | Saturn at stationary point |
| 8 | Jupiter at opposition |
| 10 | Mercury at stationary point |
| 11 | Full Moon |
| 13 | Venus at stationary point |
| 14 | Uranus at conjunction |
| 19 | Last Quarter Moon |
| 20 | Mercury at inferior conjunction |
| 22 | Lyrid Meteor Shower peaks around this time（The best visibility is before dawn on the 23nd. About 5 meteors per hour are expected. Because there is no moonlight and the timing of the maximum is good, conditions are good.） |
| 26 | New Moon |
| 29 | Showa Day [Showa-no-hi] (national holiday) |
| 30 | Venus at Greatest Brillancy |
| 2 | Mercury at stationary point |
| 3 | First Quarter Moon / Constitution Memorial Day [Kenpou-Kinen-bi] (national holiday) |
| 4 | Greenery Day [Midori-no-hi] (national holiday) |
| 5 | Children’s Day [Kodomo-no-hi] (national holiday) |
| 6 | η(Eta) Aquarid Meteor Shower peaks around this time (The best visibility will be before dawn for the 2~3 days around this date. About 5 meteors per hour are expected. Conditions are good after the Moon sets after Midnight.) |
| 11 | Full Moon |
| 18 | Greatest Western Elongation of Mercury |
| 19 | Last Quarter Moon |
| 26 | New Moon |
| 1 | First Quarter Moon |
| 3 | Greatest Western Elongation of Venus |
| 9 | Full Moon (This year’s smallest Full Moon) |
| 10 | Jupiter at stationary point |
| 15 | Saturn at opposition |
| 17 | Last Quarter Moon / Neptune at stationary point |
| 21 | Mercury at superior conjunction / Summer solstice (Sun’s ecliptic longitude 90°) |
| 24 | New Moon |
| 1 | First Quarter Moon |
| 4 | Earth passes aphelion |
| 9 | Full Moon |
| 17 | Last Quarter Moon /Ocean Day [Umi-no-hi](national holiday) |
| 23 | New Moon |
| 25 | Occultation of Mercury |
| 27 | Mars at conjunction |
| 30 | Greatest Eastern Elongation of Mercury / Aquarid δ (Delta) Meteor Shower peaks around this time (The best visibility is after midnight for 6~7 days around this date. About 5 meteors per hour are expected. Conditions are good after the Moon sets around Midnight.） |
| 31 | First Quarter Moon |
| 3 | Uranus at stationary point |
| 8 | Partial Lunar Eclipse Reference: Local Prediction of Lunar Eclipse / Full Moon |
| 11 | Mountain Day [Yama-no-hi](national holiday) |
| 12 | Mercury at stationary point |
| 13 | The Perseid Meteor Shower peaks around 4:00（The best time for viewing is before dawn on the 13th. On the order of 35 meteors per hour are expected. The Moon is bright, so conditions are bad.） |
| 15 | Last Quarter Moon |
| 22 | Total solar eclipse (not visible from Japan) Reference: Local Prediction of the Solar Eclipse / New Moon |
| 26 | Saturn at stationary point |
| 27 | Mercury at inferior conjunction |
| 28 | Traditional tanabata (traditional star festival) |
| 29 | First Quarter Moon |
| 5 | Mercury at stationary point / Neptune at opposition |
| 6 | Full Moon |
| 12 | Greatest Western Elongation of Mercury |
| 13 | Last Quarter Moon |
| 18 | Respect-for-the-Aged Day [Keiro-no-hi ](national holiday) |
| 20 | New Moon |
| 23 | Autumnal Equinox Day [Shubun-no-hi] (national holiday)/ Autumn equinox (Sun’s ecliptic longitude 180°) |
| 28 | First Quarter Moon |
| 4 | Chushu Moon |
| 6 | Full Moon |
| 8 | The October Draconid Meteor Shower peaks around this time. (The best time to observe is after sunset on the 8th. On the order of 4 meteors per hour are expected. Conditions are good for about 1 hour from when it gets dark after sunset until the Moon rises.) |
| 9 | Mercury at superior conjunction / Health-Sports Day [Taiiku-no-hi] (national holiday) |
| 10 | Occultation of Aldebaran (Mainly Northern Japan) / The Southern Taurid Meteor Shower peaks around this time. (The best time to observe is before midnight in the latter part of October, when there is no effect from moonlight. On the order of 2 meteors per hour are expected.) |
| 12 | Last Quarter Moon |
| 20 | New Moon / Uranus at opposition |
| 21 | The Orionid Meteor Shower peaks around this time. (The best time to observe is before dawn for about 4~5 days around this date. On the order of 5 meteors per hour are expected. There is no moonlight, so the conditions are very good.) |
| 27 | Jupiter at conjunction |
| 28 | First Quarter Moon |
| 3 | Culture Day [Bunka-no-hi](national holiday) |
| 4 | Full Moon |
| 11 | Last Quarter Moon |
| 12 | Occultation of Regulus / Northern Taurid Meteor Shower peaks around this time.（The best time to observe is before midnight in the latter part of November, when there is no effect from moonlight. On the order of 2 meteors per hour are expected.） |
| 18 | New Moon / Leonid Meteor Shower peaks around this time. (The best time for viewing is before dawn on the 18th. On the order of 2 meteors per hour are expected. Because there is no moonlight and the timing of the maximum is not so bad, conditons are relatively good.) |
| 23 | Neptune at stationary point / Labor Thanksgiving Day [Kinro-kansha-no-hi] (national holiday) |
| 24 | Greatest Eastern Elongation of Mercury |
| 27 | First Quarter Moon |
| 3 | Mercury at stationary point |
| 4 | Full Moon（This year’s largest Full Moon） |
| 10 | Last Quarter Moon |
| 13 | Mercury at inferior conjunction |
| 14 | Geminid Meteor Shower peaks around 16:00（The best time to observe is after midnight on the morning of the 14th. On the order of 40 meteors per hour are expected. Because there is almost no effect from moonlight and the timing of the maximum is not so bad, conditons are relatively good.) |
| 18 | New Moon |
| 22 | Saturn at conjunction / Winter solstice (Sun’s ecliptic longitude 270°) |
| 23 | Mercury at stationary point / Emperor’s Birthday [Tennou-Tanjyobi] (national holiday) |
| 26 | First Quarter Moon |
The days for the peak activities of the meteor showers are based on the predictions of IMO (the International Meteor Organization). The standard number of meteors appearing listed for a meteor shower is the maximum number per hour at the peak time that a normal person can observe if the sky is dark enough to see the Milky Way. Therefore, the number of meteors can become a fraction of this number when observing in city lights or at a time other than the peak. On the other hand, a severalfold increase in the number of meteors can be seen based on the sky condition and observers' proficiency.